The present invention relates to an optical disk apparatus and a control method thereof, for recording information on an optical disk of recordable type; such as, a CD-R, a CD-RW, etc., for example, with utilizing a semiconductor laser diode.
Conventionally, in the so-called optical disk apparatus, recording of information is conducted on the optical disk of recordable type, such as, the CD-R (i.e., the CD-Recordable), a CD-RW (i.e., the CD-ReWritable), and a DVD-RAM (i.e., the Digital Versatile Disc-Random Access Memory), for example, with using the laser diode as an optical source thereof.
Also, with such the conventional optical disk apparatus, it is possible to set up a higher linear velocity, to be the linear velocity for performing the recording; such as, the linear velocity of two (2) times, the linear velocity of four (4) times, the linear velocity of eight (8) times . . . , etc., with respect to the linear velocity when reproducing (this is assumed to be a linear velocity of one (1) time), and then the recording of information is performed at the linear velocity of that high speed set up, thereby achieving shortening of the recording time.
Further, as the method for controlling the rotation speed of the optical disk, in particular when recording the information, there are already known the followings: i.e., a CLV (Constant Linear Velocity) control method, for controlling the rotation speed of the optical disk to be constant in the linear speed at the recording position, i.e., an irradiating portion of a laser light, a CAV (Constant Angular Velocity) method, for controlling the rotating angular velocity of the optical disk to be always constant, when recording, and further a control method of exchanging the CLV method and the CAV method appropriately. For example, with the CLV method, the linear velocity when recording is the linear velocity set up, while with the CAV method, the rotation speed is controlled, so that the linear velocity at a recording position, located in a radial direction of the optical disk, does no exceed the rotation speed set up, thereby achieving the record of information.
However, with any of those methods for controlling the rotation speed, an output value of the laser necessary for recording the information increases together with an increase of the linear velocity; therefore, in a case where a high linear velocity is set up, a LD (Laser Diode) comes to be unstable in the operation thereof, and there is a problem that it fails the recording of information.
Then, for example, according to the Patent Document 1 mentioned below, there is already proposed or disclosed an optical disk recording apparatus, wherein it is possible to operate the LD stable even when the linear velocity of high speed is set up, thereby enabling to avoid the failure of recoding information onto the optical disk of the recordable type.
Japanese Patent Laying-Open No. 2002-324318 (2002); in particular in FIGS. 2 and 3 thereof
Also, such as, a semiconductor laser device and/or a device for controlling an output of a laser diode, for example, which can be applied to a laser printer, a laser scanning apparatus, etc., is also already known, for example, in the following Patent Documents 2 and 3: in which, the laser light emitted by the semiconductor laser is received by the means of an inner photodiode or an outer photodiode, so as to obtain the so-called feedback control upon an intensity of light emission of the laser diode, on the basis of an output of the light received, wherein the current supplied to the laser diode is prevented from becoming excessive, thereby preventing the laser diode from deterioration thereof.
Japanese Patent Laying-Open No. 2000-206435 (2000); in particular in FIGS. 2 and 3 thereof, and
Japanese Patent Laying-Open No. 2002-16315 (2002); in particular in FIG. 3 thereof
With such the conventional technologies as was mentioned above, however, in particular, with such the optical disk recording apparatus and a program for controlling the optical disk recoding apparatus, which are described in the former, i.e., the Patent Document 1 mentioned above, wherein while memorizing a maximum value for enabling a stable operation of the laser diode in advance, and there is provided a means for calculating out an appropriate output value of the laser, responding to the linear velocity set up, to be compared with that maximum output value memorized in advance, and in a case where it is equal or greater than that, it calculates/designates the linear velocity set up to be less than that set-up value thereof. With this, however it is impossible to detect the deterioration of the laser diode irradiating the light beam upon the optical disk when recording information thereon, and therefore it is also impossible to achieve protection of the laser diode, as well as, to deal with such the deterioration accompanying therewith, in particular, in the recording quality thereof.
On the other hand, with such the semiconductor laser device and/or the controller device for controlling an output of the laser diode, being applied into the laser scanning apparatus, which are described in the latter, i.e., the Patent Documents 2 and 3 of the conventional arts mentioned above, when the output of the laser diode is abnormal in the condition thereof, the laser diode stops the output thereof; therefore when applying this into the optical disk apparatus, it is impossible to continue the recording operation, and for this reason, there is a drawback that it brings about the deterioration in the recording quality.